Material handling implement

ABSTRACT

A clam shell material handling implement which is connectable to a back hoe type material handling apparatus is disclosed. The clam shell implement includes hinged jaws each connected to the back hoe dipstick by articulating linkages. The back hoe bucket ram is connected to the jaw hinge by a cable so that the jaws are opened and closed by operation of the bucket ram. The linkages carry a cable guiding sheave construction. The implement is connectable as a unit to the dipstick without modification of the back hoe machine.

United States Patent 1191 Barber ]*Dec. 11, 1973 [54] MATERIAL HANDLING IMPLEMENT FOREIGN PATENTS OR APPLICATIONS [751 Inventor: Claude Baker, 323,257 9/1957 Switzerland 214/147 [73] Assignee: Yaun Manufacturing Company,

Inc. Baton Rouge, Primary ExammerGerald M. Forlenza l Assistant ExaminerJerold M. Forsberg 1 Notlce: The portlonlof the term of thls AttorneyWatts, l-loffmann, Fisher & Heinke patent subsequent to Sept. 1 l, 1974, has been disclaimed. 57 ABSTRACT [22] Filed: Feb. 2, 1970 A clam shell material handling implement which is 7 connectable to a back hoe type material handling ap- [21] Appl' 7706 paratus is disclosed. The clam shell implement includes hinged jaws each connected to the back hoe [52] U.S. Cl. 214/138 R, 214/147 G ip i k by ar icul ting linkages. The back hoe bucket [51] Int. Cl E02t 3/75 ram i c nne te to the jaw hinge by a cable so that [58] Field of Search 214/138, 147, 147 G he j w ar op ne and closed by operation of the bucket ram. The linkages carry a cable guiding sheave [56] References Cited construction. The implement is connectable as a unit UNITED STATES PATENTS to the dipstick without modification of the back hoe 3,275,172 9/1966 Smith 214 147 x machme' Anderson 214/147 G 4 Claims, 4 Drawing Figures mmnnmm 3.777. 918

PE/O/Z ART INVENTOR.

CLAUDE L 542552 QMQ/ MW, M f M A TTOENE 7 5,

MATERIAL HANDLING IMPLEMENT BACKGROUND OF THE INVENTION 1. Field of the Invention I The present invention relates to material handling implements, and more specifically to cable-hydraulic operated material handling implements which are installable on back hoe type material handling machines.

2. The Prior Art Back hoes are normally equipped with a bucket which is actuated by a hydraulic bucket ram. In most machines of the type referred to, the bucket is hingedly connected to a dipstick or arm to obtain a wrist-like digging action, and the dipstick is in turn pivotally connected to a boom. The boom and the dipstick are independently movable and are actuated by hydraulic rams. The controls for the several hydraulic rams have included a number of control valve operating levers which are moved to govern the flow of hydraulic fluid to the rams associated with the bucket and with the boom and dipstick.

There are many material handling and earthworking functions which are capable of being accomplished by a back hoe except for the inability of the conventional bucket implement to perform them. For example, such machines could be used to handle logs or masses of cut sugar cane if a grab or grapple-like implement were provided on the machine. Similarly, earthworking clam shell implements are often preferable to the standard buckets.

There has been a long felt need in the industry for clam shell type implements, as well as other grab-like implements, which can be easily and simply installed on a back hoe in place of the standard bucket without major modification of the existing machine and without complication of the existing hydraulic controls.

Various proposals have been made for fulfilling this need. For example, it has been proposed to replace the standard bucket with a hydraulically actuated clam shell. These implements have been constructed with a jaw actuating hydraulic ram forming an integral part of the implement assembly.

The use of such conventional implement attachments has often required additional hydraulic controls in the operators cab. Since existing controls of a standard back hoe are complex and difficult to operate, the provision of additional controls for hydraulically operated replacement implements has resulted in further complication of the operators controls. In order to install such implements on a stardard machine, it has also been necessary to make extensive modifications of the hydraulic systems of the machines.

According to another conventional arrangement, the replacement implements have included actuating rams which are communicated to the hydraulic system of the machine by hoses which are removed from an inactive ram and connected to the implement ram. While such arrangements have not required extensive modifications to the machine or the concomitant increase in control complexity, these devices have been difficult to properly install in the field. It may be necessary for example, to drain all or part of the hydraulic system of the machine when replacing the bucket. Furthermore, contamination of the hydraulic fluid can occur when hydraulic lines are connected and disconnected in the field.

A major disadvantage of all of the foregoing proposals is that the hydraulically actuated replacement implements cannot be operatively installed easily and simply on a back hoe in place of the standard bucket. Such installation is particularly difficult to accomplish in the field. These difficulties have arisen from the necessity of modifying existing hydraulic systems or complications involving the replacement of one hydraulically operated device by another. As a result, the prior art has failed to provide a commercially practicable grab or clam shell type replacement implement for back hoes or similar machines.

SUMMARY OF THE INVENTION According to the present invention, a new and improved implement is provided for use with a back hoe or similar machine. The new implement is simple in construction and operation. It can be quickly and easily installed onthe machine, and is operable by the existing bucket ram without modification of the machine or its controls.

The new implement includes a pair of articulated jaws which are hinged together and attached to the machine by articulating links. The jaws are operated by a cable which is connected to the ram normally used to actuate the standard bucket. The new implement, including the articulating links and the cable, is detachably connected to the machine so that a standard implement on the machine is readily replaced by the new implement.

In a preferred construction, the new implement is a clamshell digging implement having a pair of digging jaws. The jaws are hinged together and connected to the end of a back hoe dipstick by link arms.

A cable extends between the jaw hinge and a bucket ram on the dipstick. When the bucket ram is operated to pull the cable, the jaws move together about the hinge to a closed position. When the bucket ram is operated in the opposite direction, the cable is relaxed and the jaws move away from each other to open under the influence of gravity.

The cable is associated with a spring tensioning device which prevents the cable from parting when the jaws cannot be closed further and the cable is tensioned by the bucket ram. This enables the jaws to swing under the influence of gravity when the dipstick and boom are raised with the jaws closed.

The link arms for one jaw carry a cable guiding structure which prevents abrading of the cable by stationary parts of the dipstick and maintains the cable properly aligned between the bucket ram and hinge. The cable guide structure preferably includes a sheave supported between the link arms and over which the cable is trained.

A conventional bucket implement can be replaced by the new implement'quickly and easily. The standard bucket is removed from a pivot construction at the end of the dipstick, and is detached from a linkage associated with the bucket ram. The link arms of the new implement are then connected to the pivot construction and the cable is attached to the bucket ram linkage. The new implement is thus connectable to the dipstick by the same connecting structures utilized for attaching a standard bucket.

The new implement can be positively forced into the earth by the dipstick. The operating cable does not interfere with this function, i.e. the rigid connections between the dipstick and implement jaws maintain the jaws in position while transmitting force from the dipstick. The new implement construction also enables the jaws to be closed by the operating cable without raising the dipstick.

A principal object of the present invention is the provision of a new and improved implement for a back hoe, or similar machine, which is of simple construction, and which is quickly and easily installed on the machine without requiring modification of the machine structure or controls.

Other objects and advantages of the present invention will be apparent from the following detailed description thereof made with reference to the accompanying drawings which form a part of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of a machine embodying the present invention;

FIG. 2 is an elevational view of a portion of the machine of FIG. 1 with parts in a different operative position;

FIG. 3 is an elevational view of a portion of the machine illustrated in FIG. 2 as seen from the plane indi-' cated by the line 3-3 in FIG. 2; and,

FIG. 4 is an elevational view similar to FIG. 2 showing a conventional arrangement of parts.

DESCRIPTION OF A PREFERRED EMBODIMENT A back hoe type apparatus embodying the present invention is illustrated by FIG. 1. Except for the attached work handling implement, which is described in detail below, the apparatus 10 is of conventional construction and includes a carrier vehicle 11 and a body 12. The body 12 is connected to the carrier vehicle by a turntable arrangement 13 so that the body is rotatable relative to the carrier about a vertical axis.

The body 12 includes an operators cab 15 and power unit 16 which houses an internal combustion engine 17 and a hydraulic system 18 which is driven from the engine 17. The body 12 additionally supports a boom hoist 20, a dipstick 21 connected to the boom hoist and an implement 22 carried by the dispstick.

The boom hoist is connected to the body 12 by a pivot construction 23 which provides a horizontal rotation axis for the boom hoist so that the boom hoist pivots in a vertical plane relative to the body. A projecting end 25 of the boom hoist is connected to the dipstick 21 by a pivot construction 26 having a horizontal axis so that the dipstick 21 is pivotable in a vertical plane relative to the boom hoist.

The hydraulic system 18 includes suitable hydraulic pumps and flow control valves actuated from the operators cab to control operation of the apparatus 10. An actuator (not shown) is associated with the turntable 13 for rotating the body 12 relative to the carrier vehicle 11. A pair of hydraulic rams 30 (only one of which is shown in FIG. 1) is provided for controlling the position of the boom hoist relative to the body. A ram 32 is connected to the boom hoist and to the dipstick for pivoting the dipstick relative to the boom hoist about the pivot 26.

A hydraulic ram 34 which normally actuates a bucket type implement (FIG. 4) is carried by the dipstick. The ram 34 includes a cylinder 36 which is pivotally connected to the dipstick and an extensible and retractable piston rod 38 which is pivotally connected to a linkage 40 connected near the projecting end of the dipstick by the pivot construction 41. The rams 30, 32, 34 are connected in hydraulic circuits with the hydraulic system 18 and control valves (not shown) by pressure hoses which are generally indicated at 42.

It is to be understood that the foregoing construction of the apparatus 10 is not limiting the invention, and that the particular structure which has been shown and described has been chosen only for the purpose of disclosing one conventional machine in which the invention can be embodied to advantage.

Referring now to FIG. 2, the implement 22 provided in accordance with the present invention includes jaws 50, 52 which are connected together by a hinge 54. The jaws 50, 52 include material receiving portions 50a, 52a, respectively. Each jaw is formed with a pair of projecting hinge knuckles 50b, 52b, respectively, at lateral sides of the jaws. A pintle or pivot bar 56 extends through the hinge knuckles of the jaws and laterally between the sides of the jaws.

The jaw 50 is connected to the dipstick by an articulating linkage 58 which includes link arms 60, 62 (FIG. 3). Each arm is connected to the jaw 50 by a pivot construction 64 which is spaced from the hinge 54. The arms 60, 62 are journaled to the end of the dipstick by a bearing construction 66.

The jaw 52 is connected to the dipstick by an articulating linkage 68 which includes-link arms 70, 72 (FIG. 3) constructed substantially the same as the arms 60, 62 described in reference to the jaw 50. Each arm 70, 72 is connected to the jaw 52 by a pivot construction 74 and journaled to the dipstick by the bearing construction 66.

A flexible force transmitting member connects the implement 22 to the ram 34 so that the jaws 50, 52 are operated between the open and closed positions by the ram 34. Preferably, the member 80 is a single cable having one end attached about the hinge bar 56. The cable is detachably connected to the linkage 40 at its other end.

The link arms 60, 62 support a guide structure 81 for the cable. The guide structure 81 supports the cable away from stationary parts of the machine while assuring alignment of the cable 80 and ram 34. The guide structure includes supports 85, 86 (FIG. 3) which project from the link arms 60, 62. The supports 85, 86 carry a laterally extending axle 87 and a rotatable sheave 90. The cable 80 is trained over the sheave 90. The guide structure 81 further includes a cable guiding roll 93 supported on an axle 94 extending between the supports 85, 86 parallel to the axle 87. The roll 93 prevents the cable from becoming untrained from the sheave when the cable slackens.

In the preferred embodiment, the cable 80 is connected to the linkage 40 by a spring construction 95 which provides limited elasticity in the connection between the bucket ram and the hinge 54 so that the cable is not overtensioned in certain operating circumstances. For example, when the jaws 50, 52 are closed and the dipstick or boom is elevated, the implement 22 tends to swing to a vertical orientation under the influence of gravity. This swinging tends to tension the cable and if the jaws are heavily loaded, the cable could part. The spring structure 95 resiliently deflects under tensile loadings which are less than the maximum permissible cable tension. This enables the implement to freely assume a vertical orientation on raising the dipstick or boom with the jaws closed and without the cable partmg.

In operation, when the piston 38 of the ram 34 is retracted, the cable 80 pulls the hinge bar 56 to a position relatively close to the projecting end of the dipstick. This results in the jaws moving about the hinge 54 to the closed position as shown in FIG. 1. The link arms 60, 62 pivot slightlyaway from the link arms 70, 72 enabling closing movement of the jaws 50, 52. When the piston 38 is extended, the tension in the cable is relaxed and the jaws pivot about the connections to their respective link arms under the force of gravity to the open-position (FIGS. 2 and 3).

Because the link arms 60, 62,70, 72 rigidly connect the dipstick and the jaws, the dipstick can positively force the jaws into the earth. Thus even though the cable 80 may be slack the link arms maintain the jaws positioned with respect to the dipstick and transmit earth penetrating forces to the jaws from the dipstick. The cable 80 is also operable to close the jaws without requiring upward movement of the dipstick. Hence, although the jaws are cable operated, they are capable of functioning in a manner equivalent to hydraulically operated jaws.

An important feature of the invention is the simplicity with which the implement 22 is, as a unit, attached to and detached from a standard dipstick or equivalent support member without modification of the machine 10.

FIG. 4 shows a conventional bucket 100 detachably connected to the dipstick at the bearing construction 66. The bucket 100 is rotatable about the bearing 66 by operation of the ram 34. A rigid connecting rod 105 extends between the bucket and the linkage 40 to control movement of the bucket about the bearing 66.

The bucket 100 can be removed from the dipstick by detaching the bucket from the bearing construction 66 and removing the connecting rod 105 from the linkage 40.

The implement 22 is then attached, as a unit, to the dipstick by connecting the link arms 60, 62 and 70, 72 to the bearing construction 66. The cable 80 is then attached to the wrist 40 to complete the assembly to the implement of the machine 10.

Although one preferred embodiment of the invention has been illustrated and described in considerable detail, the invention is not to be considered to be limited to the precise construction shown. For example, although a clam shell type digging implement is disclosed specifically, other grab-like implements such as log tongs, cane grapples, etc., can be constructed according to the principles of the invention. Various adaptations, modifications and uses of the invention may occur to those skilled in the art and it is intended to cover all such adaptations, modifications and uses which come within the scope of the invention as claimed.

What is claimed is:

1. A backhoe machine whereina backhoe shovel implement is replaced by a clam shell implement comprising:

a. a movable boom;

b. a dipstick pivotally connected to said boom for movement relative thereto;

c. a hydraulic'ram connected between said boom and said dipstick for effecting movement of said dipstick relative to said boom;

(1. backhoe shovel supporting structure on said dipstick at a projecting implement supporting end portion of said dipstick remote from said boom;

e. actuating means comprising a second hydraulic ram carried on said dipstick for actuating an implement connected to said supporting structure; and,

f. a clam shell implement connectable as a unit to said dipstick for actuation by said second ram, said clam shell implement comprising:

1. first and second material handling jaws;

2. a hinge connecting said jaws together for movement relative to each other;

3. a first rigid link pivotally connected to said first 4. a second rigid link pivotally connected to said second jaw;

5. means detachably connecting said first and second links to said shovel supporting structure for pivoting movement relative thereto;

6. a flexible substantially inextensible member connected to said hinge and detachably connected to said actuating means formoving said hinge to articulate said jaws in response to operation of said second ram; and,

7. guide means connected to one of said links for training said flexible member between said hinge and said actuating means.

2. The machine claimed in claim 1 wherein said dipstick is connected to said boom by first pivot means for enabling movement of said dipstick in a vertical plane relative to said boom, and second pivot means connecting said first hydraulic ram to said dipstick, said first pivot means being located between said second pivot means and said means for connecting said links to saidv shovel supporting structure so that said dipstick can be moved by extending said first actuator to transmit earth penetrating forces to said jaws through said links.

3. A machine as claimed in claim 1 wherein said flexible member comprises a cable and said guide means comprises a sheave supporting said cable.

4. A machine as claimed in claim 1 and further including spring means connected to said flexible memher, said spring means being resiliently yieldable for limiting stress in said flexible member. 

1. A backhoe machine wherein a backhoe shovel implement is replaced by a clam shell implement comprising: a. a movable boom; b. a dipstick pivotally connected to said boom for movement relative thereto; c. a hydraulic ram connected between said boom and said dipstick for effecting movement of said dipstick relative to said boom; d. backhoe shovel supporting structure on said dipstick at a projecting implement supporting end portion of said dipstick remote from said boom; e. actuating means comprising a second hydraulic ram carried on said dipstick for actuating an implement connected to said supporting structure; and, f. a clam shell implement connectable as a unit to said dipstick for actuation by said second ram, said clam shell implement comprising:
 1. first and second material handling jaws;
 2. a hinge connecting said jaws together for movement relative to each other;
 3. a first rigid link pivotally connected to said first jaw;
 4. a second rigid link pivotally connected to said second jaw;
 5. means detachably connecting said first and second links to said shovel supporting structure for pivoting movement relative thereto;
 6. a flexible substantially inextensible member connected to said hinge and detachably connected to said actuating means for moving said hinge to articulate said jaws in response to operation of said second ram; and,
 7. guide means connected to one of said links for training said flexible member between said hinge and said actuating means.
 2. a hinge connecting said jaws together for movement relative to each other;
 2. The machine claimed in claim 1 wherein said dipstick is connected to said boom by first pivot means for enabling movement of said dipstick in a vertical plane relative to said boom, and second pivot means connecting said first hydraulic ram to said dipstick, said first pivot means being located between said second pivot means and said means for connecting said links to said shovel supporting structure so that said dipstick can be moved by extending said first actuator to transmit earth penetrating forces to said jaws through said links.
 3. A machine as claimed in claim 1 wherein said flexible member comprises a cable and said guide means comprises a sheave supporting said cable.
 3. a first rigid link pivotally connected to said first jaw;
 4. a second rigid link pivotally connected to said second jaw;
 4. A machine as claimed in claim 1 and further including spring means connected to said flexible member, said spring means being resiliently yieldable for limiting stress in said flexible member.
 5. means detachably connecting said first and second links to said shovel supporting structure for pivoting movement relative thereto;
 6. a flexible substantially inextensible member connected to said hinge and detachably connected to said actuating means for moving said hinge to articulate said jaws in response to operation of said second ram; and,
 7. guide means connected to one of said links for training said flexible member between said hinge and said actuating means. 